摘要 |
<p>Polyester compositions are disclosed that include polyester polymers or copolymers having incorporated therein particles of one or more transition metal compounds that improve the reheat properties of the compositions. The transition metal compounds are binary compounds of a transition metal element selected from titanium, vanadium, zirconium, niobium, hafnium, and tantalum, and a non-metallic element selected from boron, carbon, and nitrogen. Processes for making such polyester compositions are also disclosed. The particles may be incorporated in the polyester by melt compounding, or may be added at any stage of the polymerization, such as during the melt-phase of the polymerization. A range of particle sizes may be used, as well as a range of particle size distributions. The polyester compositions are suitable for use in packaging made from processes in which a reheat step is desirable.</p> |